### Always-active ARST removal.

read_verilog -icells <<EOT

module top(...);

input CLK;
input [1:0] D;
output [11:0] Q;
input ARST;
input EN;

$adff #(.CLK_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff0 (.CLK(CLK), .ARST(1'b1), .D(D), .Q(Q[1:0]));
$adffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .ARST_POLARITY(1'b0), .ARST_VALUE(2'h2), .WIDTH(2)) ff1 (.CLK(CLK), .ARST(1'b0), .EN(EN), .D(D), .Q(Q[3:2]));
$adlatch #(.EN_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff2 (.EN(EN), .ARST(1'b1), .D(D), .Q(Q[5:4]));
$adff #(.CLK_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff3 (.CLK(CLK), .ARST(1'bx), .D(D), .Q(Q[7:6]));
$adffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .ARST_POLARITY(1'b0), .ARST_VALUE(2'h2), .WIDTH(2)) ff4 (.CLK(CLK), .ARST(1'bx), .EN(EN), .D(D), .Q(Q[9:8]));
$adlatch #(.EN_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff5 (.EN(EN), .ARST(1'bx), .D(D), .Q(Q[11:10]));


endmodule

EOT

design -save orig

equiv_opt -undef -assert -multiclock opt_dff
design -load postopt
select -assert-none t:*

design -load orig

equiv_opt -undef -assert -multiclock opt_dff -keepdc
design -load postopt
select -assert-count 1 t:$adff
select -assert-count 1 t:$adffe
select -assert-count 1 t:$adlatch

design -load orig
simplemap

equiv_opt -undef -assert -multiclock opt_dff
design -load postopt
select -assert-none t:*

design -load orig
simplemap

equiv_opt -undef -assert -multiclock opt_dff -keepdc
design -load postopt
select -assert-count 2 t:$_DFF_???_
select -assert-count 2 t:$_DFFE_????_
select -assert-count 2 t:$_DLATCH_???_

design -reset


### Never-active ARST removal.

read_verilog -icells <<EOT

module top(...);

input CLK;
input [1:0] D;
output [5:0] Q;
input ARST;
input EN;

$adff #(.CLK_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff0 (.CLK(CLK), .ARST(1'b0), .D(D), .Q(Q[1:0]));
$adffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .ARST_POLARITY(1'b0), .ARST_VALUE(2'h2), .WIDTH(2)) ff1 (.CLK(CLK), .ARST(1'b1), .EN(EN), .D(D), .Q(Q[3:2]));
$adlatch #(.EN_POLARITY(1'b1), .ARST_POLARITY(1'b1), .ARST_VALUE(2'h2), .WIDTH(2)) ff2 (.EN(EN), .ARST(1'b0), .D(D), .Q(Q[5:4]));

endmodule

EOT

design -save orig

equiv_opt -undef -assert -multiclock opt_dff
design -load postopt
select -assert-none t:$adff
select -assert-none t:$adffe
select -assert-none t:$adlatch
select -assert-count 1 t:$dff
select -assert-count 1 t:$dffe
select -assert-count 1 t:$dlatch

design -load orig
simplemap

equiv_opt -undef -assert -multiclock opt_dff
design -load postopt
select -assert-none t:$_DFF_???_
select -assert-none t:$_DFFE_????_
select -assert-none t:$_DLATCH_???_
select -assert-count 2 t:$_DFF_P_
select -assert-count 2 t:$_DFFE_PP_
select -assert-count 2 t:$_DLATCH_P_

design -reset